Grace Millane has been reported missing by her family.
Photograph: Michael Millane

New Zealand police are investigating the disappearance of a 22-year-old British woman during a holiday in Auckland.

The family of Grace Millane, who is from Essex and attended the University of Lincoln, say they have not heard from her since 1 December.

“Police are continuing to investigate the disappearance of missing 22-year-old English tourist Grace Millane,” said Detective Inspector Scott Beard of the Auckland city police.

The family urged anyone who had seen Millane to report her whereabouts. “Grace has been missing for five days,” wrote her brother Michael Millane on Facebook. “She has not returned to her hostel room in Auckland New Zealand and family members have had no contact since Saturday 1st December.”

Millane was reported missing at lunchtime on Wednesday and police have been piecing together her movements since her last known sighting on Saturday night.

A CCTV image of Millane was taken at 7.15pm on 1 December, at Sky City in Auckland’s CBD. In the image, Millane is seen wearing a black dress and white shoes, believed to be Converse.

Beard said Millane had not been in contact with her family for a number of days. “This is particularly out of character, especially as it was her 22nd birthday on Sunday. We are working closely with her family at this time and a number of police staff are currently working on this matter.

“Clearly this is a very stressful time for Grace’s family and the longer she remains missing the more our concern grows for her safety and wellbeing.”